4 months old child old tongue generally belongs to the physiological phenomenon, 4 months when the child has entered the oral sex period, salivary glands secretion of saliva also began to increase, saliva stored in the mouth, so that the child is always with the lips, tongue to explore the outside world. Some children begin to grow teeth, the child feels more itchy teeth bed, will unconsciously use the tongue to top the gums, which leads to the child’s performance of the symptoms of the old tongue. In addition, we have to pay attention to some pathological phenomena, such as the following: 1, the spleen and stomach have accumulated heat, this kind of children in addition to the old tongue, there are bad breath, thick tongue, bloating, constipation and other manifestations, at this time you can give the child to eat a little probiotic, such as mamma love, small PeiFeiKang, etc. 2, mouth ulcers, pay attention to the child has oral ulcers may be observed in the child’s oral cavity, the discovery of ulcers can be used vitamin B2 3, congenital stupidity, common is 21 – trisomy syndrome, is due to chromosomal abnormalities, the child in addition to the old tongue, there is mental retardation, growth and development behind, this situation has no special treatment method.